1. Field of the Invention
This invention pertains to workpiece handling, and more particularly to apparatus for loading workpieces into a machine tool.
2. Description of the Prior Art
Various equipment has been developed to automatically transport workpieces to a machine tool for processing. Such equipment varies widely to suit both the workpieces to be processed and the particular machine tools. A specialized application of workpiece handling and processing involves machines for grinding drills, end mills, taps, and similar cutting tools. For example, workpieces in the form of new drill blanks are inserted into tool holding chucks of drill grinding machines for having the drill cutting edges ground. After grinding, the drills are removed from the chucks.
In the past, it was common practice to manually load and unload drill grinding machines. However, productivity is increased considerably with the use of automatic mechanisms for loading and unloading the drills. Accordingly, many modern drill grinding machines include automatic loaders. For example, U.S. Pat. No. 4,821,463 describes a robot-like mechanism for storing, loading, and unloading drills. U.S. Pat. No. 3,711,997 shows a drill pointing machine with an automatic drill locator that includes a hopper-shuttle assembly. Other loading apparatus utilizes horizontal or vertically oriented carousels together with appropriate mechanisms for transferring the tools to and from the machine chuck.
For several reasons, the prior tool loading devices associated with drill grinding machines are somewhat deficient. One important drawback is that the prior drill loading devices occupy an undesirably large amount of space around the grinding machine. Many of the prior loaders are also undesirably complicated in their design and construction. In addition, the prior loaders are limited to handling drills of only one length on a particular setup and grinding operation. The prior loading and unloading mechanisms are also unable to handle multi-diameter drill shanks.
Consequently, further development of equipment for loading and unloading drill grinding machines is required.